Diethylcarbamazine citrate (DEC) is known as an effective treatment for bronchial asthma because of its ability to reduce eosinophil trafficking to the lung tissue. The current study aimed to potentiate the anti-allergic effect of the drug by passive immunization of the asthmatic model with anti-DEC antibody or prior treatment with quercetin (Qur). Eight mice groups were categorized into control, the model of lung asthma, treated with DEC, passively immunized with anti(α)-bovine serum albumin Ab, anti-DEC Ab, prior exposure to 10, 20, or 40 mg Qur/Kg. b.wt. Both eosinophil peroxidase (EPO) and eotaxin2 in the lung tissues were performed. Serum levels of cytokines, bronchoalveolar lavage fluid (BALF) IgE, rabbit anti-bovine serum albumin (anti-BSA), and DEC IgG in lung tissue homogenates were assayed by ELISA. Regarding the effect of anti-DEC Ab and Qur on DEC-induced recovery of histopathological alterations showed that the Ova group had peri-bronchial hyperplasia, mononuclear leukocyte infiltration, thickening in the wall of alveoli, and congested blood vessels. However, the reduction of inflammatory cells and thickened alveolar walls was dependent on the Qur dose. Qur40 enhanced the anti-allergic effect of DEC. Moreover, the present data revealed high levels of Th2 cytokines (IL-4 and IL-5) and IgE in the Ova group. An increased leukocyte infiltration/thickening of the alveolar wall and lung tissue EPO/eotaxin2 were also observed. Qur-40 could show an enhancement effect on DEC for the reduction of IL-4, IL-5, IgE, EPO, and eotaxin 2. Consequently, the IFN-γ/IL-4 ratio was increased. Qur at 40 mg/Kg could be recommended to enhance the DEC effect suggesting a novel approach for treatment.
Keywords: Anti-allergic agents; Antibodies; Asthma; Diethylcarbamazine; Quercetin.